Method of making coves and corners for plaster lath



Aug. 18, 1931. w. B. THURMAN 1,319,345

METHOD OF MAKING COVES AND CORNERS FOR PLASTER LATE Filed Oct. 18. 1927 INVENTOR I W B. Thurman BY (9% .sum

ATTORNEY Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE I WILLIAM B. THUBIAN, OI STOCKTON, CALIFORNIA, ASSIGNOB 'I'O IIBEPBOOF WALL COMPANY, 01 RENO, NEVADA, A CORPORATION METHOD OF NAKING COVES AND CORNERS FOR PLAB'I'EB LATE Application fled October 18, 1827. Serial No. 826,848.

plaster board is used which comprises a center core of plastic material to the outer surfaces of which are adhered covering sheets of heavy paper. Where plaster board or plaster lath of this type has been used in the construction of walls the problem of making ceiling coves and corner joints so as to prevent cracks at the polnts where sec- 0 tions of the plaster board or lath are brought together, has always been a serious one. A great deal of effort has been made to provide corner beads to bridge the crack between the abutting edges of the plaster board or lath. These, however, are expensive and consume a great deal of labor in the erection thereof and the result is more or less unsatisfactory.

I have therefore given a great deal of time and experiment to figuring out a wa of providing a method whereby this condition may be obviated, and have at last produced a method whereby these cracks may be covered and a perfectly smooth and continuous surface provided by use of the wall board or lath itself and Without the necessity of the addition of any beads or like devices.

A further object of the invention is to produce a simple and inexpensive method and yet one which will be exceedingly effectice for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. 1 shows in dotted lines the corner of a room, with a piece of wall board mounted in the corner and showing how by my improved method the structure of the wall board itself may be used to provide a perfectly smooth continuous and unbroken corner joint.

Fig. 2 is a similar view of a cove ceilin showing a plece of wall boardlikewise use to make the cove but providing a. continuous and unbroken surface without cracks.

In carrying out my improved invention I make use of one of the inherent elements of the plaster board itself, namelyone of the outer surface sheets of paper-.to provide the covering for the corner or cove joints. To this end, if the board is to be used in the corner, I cut through the back surface sheet 1 of paper with a knife or other desirable instrument along the line where the corner is to be made. I then break the center core A along the line of this cut through to the front surface sheet of paper 2, but not through the said front sheet. This leaves the front sheet perfectly intact. I then bend. the plaster board at this broken through line to form the corner. When this is done and the plaster board is secured in position it leaves the front surface sheet 2 of the paper continuous and unbroken along both sides of the angle of the corner and directly across the angle itself, as clearly shown in Fig. 1. Thus when the board is papered or plastered over or left in its natural state there is no possibility of any crack in the plaster or paper occuring at the corner joint.

In Fig. 2 is shown the application of the same principle to the making of the cove ceiling. Under these conditions the back surface sheet 3 is out along a number of lines as shown and the core B is broken through from the back at such points but not through the front surface sheet 4 so that when the board is flexed at the broken through places and secured to the back studding or framework to make the cove or ceiling the front surface sheet 4 remains unbroken and presents an absolutely smooth and continuous surface to receive the paper or plaster and will prevent any cracks occurring" in the sibility of cracks at corners or in ceiling coves, and also at the same time to provide a very smooth, unbroken wall surface at these points.

From the foregoing description it will be readily seen that I have produced such a method as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred application of the method, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

A method of preparing a sheet of wallboard for the formation of coves and corners, the wallboard consisting of front and back surface sheets of paper, and a center core of plaster or like material, comprising first cutting the back sheet of the paper along a line and then fracturing the core along said line; leaving the front sheet intact whereby the latter sheet may then be bent or curved along said line to separate the fractured core parts along the line of fracture so that the board may be built into coves or corners without strain or fracture of the front sheet.

In testimony whereof I aflix my signature.

WILLIAM B. THURMAN. 

